Introduction: Improving psychological characteristics, among the most important being marital satisfaction and cognitive flexibility, in married employees of the welfare office is of great importance due to their stresses. The aim of this research was to investigate the effectiveness of acceptance and commitment therapy on marital satisfaction and cognitive flexibility among married employees of the welfare office.Methods: The present research was semi-experimental with a pre-test and post-test with control groups. The statistical population included all married employees of the welfare office of Varamin city, during year 2016. A total of 30 individuals were selected by the available sampling method and randomly assigned to two equal groups. The experimental group underwent 8 sessions of 90 minutes educated by Bach and Moran’s acceptance and commitment therapy. Both groups completed the questionnaires of Olson and Flowers’s marital satisfaction and Dennis and Vander Wal’s cognitive flexibility as a pre-test and post-test. The data were analyzed by multivariate analysis of covariance and univariate analysis of covariance methods.Results: The findings showed that there was a significant difference between experimental and control groups in two variables of marital satisfaction and cognitive flexibility. In the other words, acceptance and commitment therapy significantly led to an increase in marital satisfaction and cognitive flexibility of married employees (p≤0/05).Conclusions: Regarding the findings of this research, counselors and therapists could use acceptance and commitment therapy to improve marital satisfaction and cognitive flexibility.